Internal-type wrench for pipes and the like

ABSTRACT

In an internal-type wrench there is provided a body having three faces arranged at 120* to each other in a generally triangular shape about a common center. Each face has a bearing surface over which a circular bearing member is rolled along the face for wedging engagement into a converging socket area defined by the inner wall surface of the pipe section and an opposed bearing surface to impart both radial and tangential forces to the pipe section with the tangential forces increasing and the radial forces decreasing as torque is increased. The bearing surfaces may be straight, convexly curved, or concavely curved in relation to the associated face with the maximum tangential forces being derived by using concavely curved bearing surfaces. The bearing members are ball-shaped or roller-shaped and retained by opposed inwardly projecting overhanging portions on each side of an open slot through which a portion of the bearing member projects. The wrench body is stepped or double-ended to accomodate multiple sizes on a single body.

United States Patent [191 Streander 1 Jan. 21, 1975 INTERNAL-TYPE WRENCH FOR PIPES AND THE LIKE [75] Inventor: George W. Streander, Alamogordo,

N. Mex.

[73] Assignee: Designs Systems, Inc., Alamogordo,

N. Mex.

22 Filed: July 26,1973

21 Appl. No.: 382,753

Primary ExaminerJames L. Jones, Jr. Attorney, Agent, or Firm--Ancel W. Lewis, Jr.

[57] ABSTRACT In an internal-type wrench there is provided a body having three faces arranged at 120 to each other in a generally triangular shape about a common center. Each face has a bearing surface over which a circular bearing member is rolled along the face for wedging engagement into a converging socket area defined by the inner wall surface of the pipe section and an opposed bearing surface to impart both radial and tangential forces to the pipe section with the tangential forces increasing and the radial forces decreasing as torque is increased. The bearing surfaces may be straight, convexly curved, or concavely curved in relation to the associated face with the maximum tangential forces being derived by using concavely curved bearing surfaces. The bearing members are ballshaped or roller-shaped and retained by opposed inwardly projecting overhanging portions on each side of an open slot through which a portion of the bearing member projects. The wrench body is stepped or double-ended to accomodate multiple sizes on a single body.

19 Claims, 16 Drawing Figures PATENTEI] JANZ I I975 SHEET 10F 2 INTERNAL-TYPE WRENCH FOR PIPES AND THE LIKE BACKGROUND OF THE INVENTION This invention relates generally to wrench-type tools and more particularly to novel and improved internaltype wrenches for loosening corroded or broken pipe sections and the like by applying the torque to the inside thereof in such a way as not to damage the fixture to which the pipe section is connected.

Machinists, mechanics, plumbers and all those concerned with the removal of a section of threaded pipe from another section of pipe, from a valve or any mechanical device or fixture into which it is threaded frequently encounter conditions of damage or corrosion which make such removal difficult. Attempts to disconnect or remove this type of pipe section frequently cause a break just at the point of entry into the joint. If this occurs, it is then necessary to remove the broken part from the valve or joint without damaging the valve, joint or associated threads.

Accordingly, it is a general object of this invention to provide a novel internal-type wrench for pipe sections and the like which is particularly effective in removing pipe sections which have been broken at the joint.

Another object of this invention is to provide a novel internal wrench for pipes and the like which is highly efficient in applying the necessary torque to the pipe to effect removal without damage to the fixture to which it is attached.

Yet a further object of this invention is to provide a novel internal-type wrench characterized by having at least three bearing members rollable along bearing surfaces arranged at 120 degree intervals to each other relative to a common center and urge a portion of an associated bearing member into a converging socket area formed by a bearing surface and the wall of the pipe in a wedging engagment effecting both radial and tangential forces on the pipe section.

In accordance with the present invention in one preferred form shown there is provided a hexagonalshaped body having six faces arranged at 60 intervals with three faces arranged in a triangular manner normal to three radial lines from the center of the body at 120 to each other about the center of the body and formed with bearing surfaces extending along each face arranged to carry circular bearing members retained on the body by opposed inwardly projecting overhanging portions on opposite sides of a slot through which a portion of the bearing member projects. The projecting portions of the bearing members are rolled into a converging socket area formed by the inner wall of the pipe section and the opposed bearing surface as torque is applied to the body to apply both radial and tangential forces to the pipe section with the radial forces decreasing and the tangential forces increasing as the torque is increased. In other forms shown, the bearing surfaces are convexly curved and concavely curved along the associated face and the bearing members may be of the ball-type or roller-type. Multiple wrenches on a single body are provided by double-ended and stepped body configurations.

Other objects, advantages and capabilities of the present invention will become more apparent as the description proceeds taken in conjunction with the acompanying drawings in which:

FIG. 1 is a perspective view of an internal-type wrench embodying features of the present invention;

FIG. 2 is a perspective view of the wrench shown in FIG. I inserted into a pipe section and being turned by a socket wrench;

FIG. 3 is a side elevation view of the wrench shown in FIGS. 1 and 2 shown inserted into the pipe section;

FIG. 4 is a sectional view taken along lines 44 of FIG. 3;

FIG. 5 is a sectional view taken along lines 5-5 of FIG. 4;

FIG. 6 is a side elevation view of yet another form of wrench having concavely curved races shown inserted into a pipe section;

FIG. 7 is a sectional view taken along lines 7-7 of FIG. 6;

FIG. 7a is an enlarged sectional view of FIG. 7;

FIG. 8 is a sectional view taken along lines 88 of FIG. 7;

FIG. 8a is an enlarged sectional view of FIG. 8 with the ball bearing member removed;

FIG. 9 is a side elevation view of yet another form of wrench having convexly curved races shown inserted into a pipe section;

FIG. 10 is a sectional view taken along lines 10-10 of FIG. 9;

FIG. 11 is a sectional view taken along lines 11-11 of FIG. 10;

FIG. 12 is a side elevation view of a double-ended wrench;

FIG. 13 is a side elevation view of a three-stepped wrench for accommodating three different pipe sizes;

FIG. 14 is a fragmentary view showing the use of a roller-type bearing member with a circular transverse cross section as an alternative to the spherical ball bearing members shown in the forms of wrenches of FIGS. 1 13.

Referring now to the drawings, the wrench shown in FIGS. 1 5 is comprised of an elongated body 11 having a generally hexagonal shape with a head portion 12 at one end and a shank portion 13 at the other end. The hexagonal-shaped body 11 has six faces each designated 14 forming six corners each designated 15. The corners of the head portion 12 are beveled or rounded off at 16 so that the head portion is of a size which is slightly smaller than the inner diameter of the pipe section represented at P of a selected size so that the head portion inserts thereinto in a relatively close-fitting sliding relationship. Each corner 15 has a 45 chamber 20 at both ends. In a preferred form, the body is preferably made of hardened steel and has a dimension to insert into a conventional pipe size.

Along each of the three alternate faces of the sixsided head section located at to each other, a hardened bearing surface or raceway 17 is provided. In the form shown in FIGS. 1 5 this bearing surface or raceway 17 is a round hole drilled below the face transverse to the longitudinal axis of the body and parallel to the associated hexagonal face to form a bearing suface that is straight in relation to the associated hexagonal face. The hole is drilled to a depth to form a socketlike circular raceway area having greater span than a semicircle and forming a pair of opposed inwardly projecting overhanging portions 18 and 19 which serve to retain the ball bearing member 21 and define an open slot through which a portion of the associated ball bearing member projects outwardly beyond the associated hexagonal-face to engage the inside of the pipe section. The depth of the raceway and ball bearings are sized so that the ball bearing member will very slightly frictionally engage the pipe section in the centered or neutral position at the center of the bearing surface 17 as shown in full lines in the drawings.

The hexagonal-shaped shank portion 13 is sized to have a conventional socket-type wrench represented at 22 fit thereover and apply a torque thereto. As the body 11 is turned the ball bearing members roll into a convergent socket area between the bearing surface 17 and the inside of the pipe section P and seat themselves therein to impart torque to the pipe sections. The bearing member 21 will gradually depress into the pipe section and in an extreme position it depresses into the pipe section as represented in dashed lines at 21 in FIG. 4.

In another form of wrench shown in FIGS. 6, 7, 7a, 8 and 8a, a wrench body designated by numeral 31 and generally similar in form to wrench body 11 as above described is provided with three bearing surfaces 32 which are concavely curved in relation to alternate hex-faces along which is rolled an associated ball bearing member 33. In this form, the inwardly projecting overhanging portions 35 and 36 are more pronounced to retain the bearings and are formed by a staking operation in which a portion of the body is deformed in a direction inwardly toward the slot. This deformation is a machine operation or the like in which grooves or channels are formed represented at 37 and 38. As best seen in FIG. 80, these channels 37 and 38 are slightly inwardly of the slot and are formed by the use of a chisel-like tool or the like and each channel extends the length of the hex-face to facilitate the retention of the ball bearing member in the concavely curved bearing surface or raceway 32. Again a turning of the body causes the bearing member 33 to roll along the bearing surface 32 and wedge against the pipe section depressing thereinto as the torque increases as represented at 33.

sin y l.349/l.03l sin x 1.3084 sin x TABLE II CONCAVELY CURVED RACEWAY FORCE x sin x sin. y cos. y RADIAL TANGEN- TIAL .09 .IZ .99 .99F .12F l0 .I7 .22 .98 .98F .22F .26 .34 .94 .94F .34F .35 .46 .89 .89F .46F .44 .58 .8I .8IF .58F .50 .66 .76 .76F .66F

A comparison of the tangential forces for a wrench with a straight raceway as shown in FIGS. 1 5 and a concavely curved raceway as shown in FIGS. 6 8 in the above Tables I and II and with reference to FIG. 7a

shows that the radial forces applied to the pipe section P decrease and the tangential forces applied to the pipe x section decrease as torque applied to the body increases. In FIG. 7a, the triangle oab with angle x depicts the radial force 0a and the tangential force ah for the straight raceway towards the end of the turning motion where the bearing member 33 is depressed into the pipe section P. Here the angle x equals 30 so that the radial force equals 0.87F and the tangential force equals 0.50F. This is shown at the top of Table I.

For the concavely curved raceway the angle of attack against the pipe section of the ball bearing member is different and is given by angle y 41. Triangle vac with angle y depicts the radial force 0a and the tangential force ac. Here the radial force equals 0.76F and the tangential force equals 0.66F. This is given at the bottom of Table I. Thus, for the concavely curved raceway or bearing surface the radial force is less and the tangential force is greater than with the straight raceway for the same ball bearing positions.

Table II shows the relative forces for different angles of attack for the concavely curved raceway to illustrate the decrease in radial force and the increase in tangential force in 5 increments for angles from 5 to 30.

In a third form a wrench shown in FIGS. 9 11, there is provided a wrench body 41 again similar in form to that of bodies 11 and 31 above described but having convexly curved bearing surface 42 over which ball bearing members 43 roll. Again in this form the pair of opposed inwardly projecting overhanging portions 45 and 46 are staked or deformed inwardly by provision of grooves 47 and 48 just outside the center slot through which the ball bearing member 43 project. The convex bearing surface 42 provides a socket area which is less convergent than the straight or concave bearing surfaces so that the bearing member 43 does not depress into the pipe section as for in the extreme positions shown indashed lines at 43.

Reference is now made to the modifications of the above described internal wrenches shown in FIGS. 12 and 13. In FIG. 12, there is shown a wrench body 51 having an intermediate hexagonal-shape shank portion 52 to which a wrench may apply torque and hexagonalshaped head portions 53 and 54 at each end. These head portions 53 and 54 may fit the same size of pipe as shown but may be of different sizes according to need. The construction of the head sections are shown as similar to head section 12 above described and may also have either convexly or concavely curved bearing surfaces.

In FIG. 13 there is shown a stepped wrench having a wrench body 61 with a hexagonal-shaped shank portion 62 at one end and three head sections of progressively decreasing sizes designated 63, 64 and 65. Typically, these could be for l/4 inch, 3/8 inch and H2 inch pipe sections so that three different pipes could be handled by a single wrench body.

Referring now to FIG. 14, an alternative bearing arrangement includes a wrench body 71 having a hexface 72 in which there is a supported roller-type bearing member 73. This roller-type bearing member 73 has a circular transverse cross section and slides along a channel-shaped bearing surface 74 formed in the 5 body 71 with a portion of the roller projecting above scribed to wedge the bearing members into the socket area in the same manner as the ball bearing members. The wrench body 71 is provided with opposed C-shape undercut sections 75 and 76 facing one another leaving inwardly projecting overhanging portions 75 a and 76a, respectively, on opposite sides of an open slot which slidably retain shaft sections 73a of a reduced diameter so that the roller bearing will slide along bearing surface 74 in the same manner as the ball bearing members above described. An advantage of the roller-type bearing member 73 is increased surface contact with the pipe section. An alternative form of roller bearing could have outwardly tapered shaft portions fitted in a complementary V-shape undercut at the sides of the slot.

In the operation of the above-described wrenches, the head portions carrying the bearing members are inserted into a pipe section of the proper size and torque is applied to the shank section. Upon insertion, the bearing members are in a centered position and slightly frictionally engage the inner surface of the pipe section. As torque is applied to the body, (For example, in a clockwise direction as shown in FIG. 7a), the ball members 33 move in a direction opposite that of the rotation of the body into the converging socket area between the bearing surfaces and inner arcuate surface of the pipe and seat themselves against the pipe wall. As further torque is applied there is a changing action or a kinematic action taking place as the ball move further into the converging socket area with a change in the force or pressure applied to the pipe so that the tangential forces increase and the radial forces decreases as above described with reference to Tables I and II.

Internal-type wrenches made in accordance with the present invention have been found to be highly effective in removing broken pipe sections and the like. The ball and roller-type bearing members with a circular transverse cross section tend not to jam or cause undue distortion of a pipe or threads. The concavely curved raceway has shown a mechanical advantage, is more efficient and exhibits a higher shearing strength over the straight and convexly curved raceway. The torque applied may obtain several thousand inch-pounds even by hand pressures. The present wrench will work in either direction, is stronger, simpler and less expensive to manufacture than previously known tools of this type.

Although the present invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made by way of example and that changes in details of structure may be made without departing from the spirit thereof.

I claim:

1. In an internal-type wrench for applying torque to a pipe section having an inner wall surface and the like, the combination comprising:

a body having three faces arranged at about 120 to each other in a generally triangular manner about a common center, each said face being provided with a bearing surface;

a generally circular bearing member rollable over each bearing surface into a converging socket area defined by the inner wall surface of a pipe section into which the body is inserted and an opposed bearing surface, each said bearing surface being of a corresponding shape on each side of its midpoint and arranged in relation to the inner wall surface to afford free movement of each bearing member along an associated bearing surface, radially in and out in relation to the axis of the body and rotation about the axis of the bearing member to impart both radial and tangential forces to the pipe section in either direction as a torque is applied to the body with the tangential forces applied to the pipe section increasing and the radial forces applied to the pipe section decreasing as the torque applied to the body is increased, each said bearing surface being recessed in the associated face of the body in a recess having a pair of opposed inwardly projecting bearing member retaining portions on opposite sides of an open slot through which a portion of the associated bearing member projects.

2. In an internal-type wrench as set forth in claim I wherein said recess is generally arcuate in shape and greater in span than a semi-circle to form a pair of opposed inwardly projecting overhanging portions for retaining the bearing member during rolling movement thereof and leaving a center slot through which a portion of the bearing member projects.

3. In an internal-type wrench as set forth in claim I wherein said three faces are arranged normal to three radial lines from the common center at 120 intervals.

4. In an internal-type wrench as set forth in claim I wherein said body is hexagonal-shaped with six faces arranged normal to radial lines from the common center arranged at intervals, alternate of said faces being formed with said bearing surfaces and carrying said bearing members.

5. In an internal-type wrench as set forth in claim 4 wherein the external dimension of at least a portion of the body at the corners is slightly smaller than the inner diameter of the pipe section so as to releasably insert thereinto.

6. In an internal-type wrench as set forth in claim I wherein each of said bearing members has a circular transverse cross section.

7. In an internal-type wrench as set forth in claim I wherein each of said bearing members is generally ballshaped.

8. In an internal-type wrench as set forth in claim I wherein each said bearing member is generally rollershaped.

9. In an internal-type wrench as set forth in claim I wherein each of said bearing surfaces is arranged generally on a concave curve along the associated face.

10. In an internal-type wrench as set forth in claim 9 wherein a portion of the body adjacent the bearing member is deformed inwardly to retain said bearing member in place for movement over the bearing surface.

II. In an internal-type wrench as set forth in claim 1 wherein each of said bearing surfaces is arranged generally straight along the associated face.

12. In an internal-type wrench as set forth in claim I wherein each of said bearing surfaces is arranged generally in a convex curve along the associated face.

13. In an internal type wrench as set forth in claim 12 wherein a portion of the body adjacent the bearing member is deformed inwardly to retain said bearing member in place for movement over the bearing surfaces.

14. In an internal-type wrench as set forth in claim 1 wherein said body is made of a hardened steel.

15. In an internal-type wrench as set forth in claim 1 wherein said body has a shank portion sized and shaped to receive a wrench for applying torque thereto.

16. In an internal-type wrench as set forth in claim 1 wherein said body is double-ended and has the three faces arranged in a generally triangular manner and have associated bearing members at each end with a shank portion between the ends.

17. In an internal-type wrench as set forth in claim 1 wherein said body is stepped along the length thereof with each step having three faces arranged in a generally triangular manner and associated bearing members to accomodate pipe sections of different size with a single body.

18. An internal-type wrench for applying torque to a pipe section having an inner wall surface and the like comprising:

an elongated body having a generally hexagonal shape with a head portion at one end and a shank portion at the other end, said head portion having alternate faces each provided with a bearing surface, each bearing surface being recessed in the face of the body in a circular recess forming a raceway with a pair of opposed inwardly projecting overhanging portions retaining members on opposite sides of an open slot; and

a bearing member having a circular transverse cross section rollable over the bearing surface in each recess and projecting above the associated slot to engage the surface of the pipe section, said bearing members being rollable over each bearing surface into a converging socket area defined by the inner wall surface of a pipe section into which the body is inserted and an opposed bearing surface to impart both radial and tangential forces to the pipe section to turn the pipe section as a torque is applied to the body with the tangential forces applied to the pipe section increasing and the radial forces applied to the pipe section decreasing as the torque applied to the body is increased.

19. An internal-type wrench as set forth in claim 18 wherein the bearing surfaces are curved in relation to the faces and the body is staked on each side of the slot with a groove so as to deform the overhanging portions inwardly to retain the bearing members in the race- 

1. In an internal-type wrench for applying torque to a pipe section having an inner wall surface and the like, the combination comprising: a body having three faces arranged at about 120* to each other in a generally triangular manner about a common center, each said face being provided with a bearing surface; a generally circular bearing member rollable over each bearing surface into a converging socket area defined by the inner wall surface of a pipe section into which the body is inserted and an opposed bearing surface, each said bearing surface being of a corresponding shape on each side of its midpoint and arranged in relation to the inner wall surface to afford free movement of each bearing member along an associated bearing surface, radially in and out in relation to the axis of the body and rotation about the axis of the bearing member to impart both radial and tangential forces to the pipe section in either direction as a torque is applied to the body with the tangential forces applied to the pipe section increasing and the radial forces applied to the pipe section decreasing as the torque applied to the body is increased, each said bearing surface being recessed in the associated face of the body in a recess having a pair of opposed inwardly projecting bearing member retaining portions on opposite sides of an open slot through which a portion of the associated bearing member projects.
 2. In an internal-type wrench as set forth in claim 1 wherein said recess is generally arcuate in shape and greater in span than a semi-circle to form a pair of opposed inwardly projecting overhanging portions for retaining the bearing member during rolling movement thereof and leaving a center slot through which a portion of the bearing member projects.
 3. In an internal-type wrench as set forth in claim 1 wherein said three faces are arranged normal to three radial lines from the common center at 120* intervals.
 4. In an internal-type wrench as set forth in claim 1 wherein said body is hexagonal-shaped with six faces arranged normal to radial lines from the common center arranged at 60* intervals, alternate of said faces being formed with said bearing surfaces and carrying said bearing members.
 5. In an internal-type wrench aS set forth in claim 4 wherein the external dimension of at least a portion of the body at the corners is slightly smaller than the inner diameter of the pipe section so as to releasably insert thereinto.
 6. In an internal-type wrench as set forth in claim 1 wherein each of said bearing members has a circular transverse cross section.
 7. In an internal-type wrench as set forth in claim 1 wherein each of said bearing members is generally ball-shaped.
 8. In an internal-type wrench as set forth in claim 1 wherein each said bearing member is generally roller-shaped.
 9. In an internal-type wrench as set forth in claim 1 wherein each of said bearing surfaces is arranged generally on a concave curve along the associated face.
 10. In an internal-type wrench as set forth in claim 9 wherein a portion of the body adjacent the bearing member is deformed inwardly to retain said bearing member in place for movement over the bearing surface.
 11. In an internal-type wrench as set forth in claim 1 wherein each of said bearing surfaces is arranged generally straight along the associated face.
 12. In an internal-type wrench as set forth in claim 1 wherein each of said bearing surfaces is arranged generally in a convex curve along the associated face.
 13. In an internal type wrench as set forth in claim 12 wherein a portion of the body adjacent the bearing member is deformed inwardly to retain said bearing member in place for movement over the bearing surfaces.
 14. In an internal-type wrench as set forth in claim 1 wherein said body is made of a hardened steel.
 15. In an internal-type wrench as set forth in claim 1 wherein said body has a shank portion sized and shaped to receive a wrench for applying torque thereto.
 16. In an internal-type wrench as set forth in claim 1 wherein said body is double-ended and has the three faces arranged in a generally triangular manner and have associated bearing members at each end with a shank portion between the ends.
 17. In an internal-type wrench as set forth in claim 1 wherein said body is stepped along the length thereof with each step having three faces arranged in a generally triangular manner and associated bearing members to accomodate pipe sections of different size with a single body.
 18. An internal-type wrench for applying torque to a pipe section having an inner wall surface and the like comprising: an elongated body having a generally hexagonal shape with a head portion at one end and a shank portion at the other end, said head portion having alternate faces each provided with a bearing surface, each bearing surface being recessed in the face of the body in a circular recess forming a raceway with a pair of opposed inwardly projecting overhanging portions retaining members on opposite sides of an open slot; and a bearing member having a circular transverse cross section rollable over the bearing surface in each recess and projecting above the associated slot to engage the surface of the pipe section, said bearing members being rollable over each bearing surface into a converging socket area defined by the inner wall surface of a pipe section into which the body is inserted and an opposed bearing surface to impart both radial and tangential forces to the pipe section to turn the pipe section as a torque is applied to the body with the tangential forces applied to the pipe section increasing and the radial forces applied to the pipe section decreasing as the torque applied to the body is increased.
 19. An internal-type wrench as set forth in claim 18 wherein the bearing surfaces are curved in relation to the faces and the body is staked on each side of the slot with a groove so as to deform the overhanging portions inwardly to retain the bearing members in the raceways. 